Have you noticed the recent articles in the New York Times about staged photographs, specifically the veracity of Robert Capa's famous Falling Soldier photo? As this NYT blog post and anyone who deals with historical photographs can tell you, photographers 'enhancing' their subject matter is nothing new.
The Carter has several 19th century photographs where the action is most certainly staged:
Alexander Gardner, Home of a Rebel Sharpshooter, Gettysburg, albumen silver print, 1863
This is the same photograph described in the second NYT link. Gardner made the mistake of taking two photographs of the same soldier in different locations.
William Notman, Asleep at the Cabana, albumen silver print, ca. 1865
This 'outdoor' scene was set up inside the photographer’s studio!
Edited to add: This photo is on view in the Carter's photography galleries until January 2010 as part of the exhibition Masterworks of American Photography: Moments in Time.
Unknown artist, [Soldiers in staged fight], ambrotype with applied color, ca. 1863
This medium’s slow exposure speed tells us this fight is staged – "action" shots were impossible with the technology of the time.